Mutant Huntingtin Drives Development of an Advantageous Brain Early in Life: Evidence in Support of Antagonistic Pleiotropy.

OBJECTIVE: Huntington's disease (HD) is a neurodegenerative disease caused by a triplet repeat expansion within the gene huntingtin (HTT). Antagonistic pleiotropy is a theory of aging that posits that some genes, facilitating individual fitness early in life through adaptive evolutionary changes, also augment detrimental aging-related processes. Antagonistic pleiotropy theory may explain a positive evolutionary pressure toward functionally advantageous brain development that is vulnerable to rapid degeneration. The current study investigated antagonistic pleiotropy in HD using a years-to-onset paradigm in a unique sample of children and young adults at risk for HD. METHODS: Cognitive, behavioral, motor, and brain structural measures from premanifest gene-expanded (n = 79) and gene nonexpanded (n = 112) participants (6-21 years) in the Kids-HD study were examined. All measures in the gene-expanded group were modeled using a mixed-effects regression approach to assess years-to-onset-based changes while controlling for normal growth. Simultaneously, structure-function associations were also examined. RESULTS: Decades from motor onset, gene-expanded participants showed significantly better cognitive, behavioral, and motor scores versus gene nonexpanded controls, along with larger cerebral volumes and cortical features. After this initial peak, a prolonged deterioration was observed in both functional and structural measures. Far from onset, brain measures were positively correlated with functional measures, supporting the view that functional advantages were mediated by structural differences. INTERPRETATION: Mutant HTT may drive the development of a larger than normal brain that subserves superior early-life function. These findings support the antagonistic pleiotropy theory of HTT in HD, where this gene drives early advantage followed by accelerated aging processes. ANN NEUROL 2024.

The Cerebellar Cognitive Affective/Schmahmann Syndrome Scale in Spinocerebellar Ataxias.

The Cerebellar Cognitive Affective/Schmahmann Syndrome (CCAS) manifests as impaired executive control, linguistic processing, visual spatial function, and affect regulation. The CCAS has been described in the spinocerebellar ataxias (SCAs), but its prevalence is unknown. We analyzed results of the CCAS/Schmahmann Scale (CCAS-S), developed to detect and quantify CCAS, in two natural history studies of 309 individuals Symptomatic for SCA1, SCA2, SCA3, SCA6, SCA7, or SCA8, 26 individuals Pre-symptomatic for SCA1 or SCA3, and 37 Controls. We compared total raw scores, domain scores, and total fail scores between Symptomatic, Pre-symptomatic, and Control cohorts, and between SCA types. We calculated scale sensitivity and selectivity based on CCAS category designation among Symptomatic individuals and Controls, and correlated CCAS-S performance against age and education, and in Symptomatic patients, against genetic repeat length, onset age, disease duration, motor ataxia, depression, and fatigue. Definite CCAS was identified in 46% of the Symptomatic group. False positive rate among Controls was 5.4%. Symptomatic individuals had poorer global CCAS-S performance than Controls, accounting for age and education. The domains of semantic fluency, phonemic fluency, and category switching that tap executive function and linguistic processing consistently separated Symptomatic individuals from Controls. CCAS-S scores correlated most closely with motor ataxia. Controls were similar to Pre-symptomatic individuals whose nearness to symptom onset was unknown. The use of the CCAS-S identifies a high CCAS prevalence in a large cohort of SCA patients, underscoring the utility of the scale and the notion that the CCAS is the third cornerstone of clinical ataxiology.

Longitudinal Clinical and Biological Characteristics in Juvenile-Onset Huntington's Disease.

BACKGROUND: Juvenile-onset Huntington's disease (JOHD) is a rare form of Huntington's disease (HD) characterized by symptom onset before the age of 21 years. Observational data in this cohort is lacking. OBJECTIVES: Quantify measures of disease progression for use in clinical trials of patients with JOHD. METHODS: Participants who received a motor diagnosis of HD before the age of 21 were included in the Kids-JOHD study. The comparator group consisted of children and young adults who were at-risk for inheriting the genetic mutation that causes HD, but who were found to have a CAG repeat in the non-expanded range (gene non-expanded [GNE]). RESULTS: Data were obtained between March 17, 2006, and February 13, 2020. There were 26 JOHD participants and 78 GNE participants who were comparable on age (16.03 vs. 14.43, respectively) and sex (53.8% female vs. 57.7% female, respectively). The mean annualized decrease in striatal volume in the JOHD group was -3.99% compared to -0.06% in the GNE (mean difference [MD], -3.93%; 95% confidence intervals [CI], [-4.98 to -2.80], FDR < 0.0001). The mean increase in the Unified Huntington's Disease Rating Scale Total Motor Score per year in the JOHD group was 7.29 points compared to a mean decrease of -0.21 point in the GNE (MD, 7.5; 95% CI, [5.71-9.28], FDR < 0·0001). CONCLUSIONS: These findings demonstrate that structural brain imaging and clinical measures in JOHD may be potential biomarkers of disease progression for use in clinical trials. Collaborative efforts are required to validate these results in a larger cohort of patients with JOHD. © 2022 International Parkinson and Movement Disorder Society.

The S-Factor, a New Measure of Disease Severity in Spinocerebellar Ataxia: Findings and Implications.

Spinocerebellar ataxias (SCAs) are progressive neurodegenerative disorders, but there is no metric that predicts disease severity over time. We hypothesized that by developing a new metric, the Severity Factor (S-Factor) using immutable disease parameters, it would be possible to capture disease severity independent of clinical rating scales. Extracting data from the CRC-SCA and READISCA natural history studies, we calculated the S-Factor for 438 participants with symptomatic SCA1, SCA2, SCA3, or SCA6, as follows: ((length of CAG repeat expansion - maximum normal repeat length) /maximum normal repeat length) × (current age - age at disease onset) × 10). Within each SCA type, the S-Factor at the first Scale for the Assessment and Rating of Ataxia (SARA) visit (baseline) was correlated against scores on SARA and other motor and cognitive assessments. In 281 participants with longitudinal data, the slope of the S-Factor over time was correlated against slopes of scores on SARA and other motor rating scales. At baseline, the S-Factor showed moderate-to-strong correlations with SARA and other motor rating scales at the group level, but not with cognitive performance. Longitudinally the S-Factor slope showed no consistent association with the slope of performance on motor scales. Approximately 30% of SARA slopes reflected a trend of non-progression in motor symptoms. The S-Factor is an observer-independent metric of disease burden in SCAs. It may be useful at the group level to compare cohorts at baseline in clinical studies. Derivation and examination of the S-factor highlighted challenges in the use of clinical rating scales in this population.

Global and Regional White Matter Fractional Anisotropy in Children with Chronic Kidney Disease.

OBJECTIVE: To investigate the associations between neurocognition and white matter integrity in children with chronic kidney disease (CKD). STUDY DESIGN: This cross-sectional study included 17 boys (age 6-16 years) with a diagnosis of mild to moderate (stages 1-3, nondialysis/nontransplant) CKD because of congenital anomalies of the kidney and urinary tract and 20 typically developing community controls. Participants underwent 3T neuroimaging and diffusion-weighted magnetic resonance imaging to assess white matter fractional anisotropy. Multivariable linear regression models were used to evaluate the impact of each group (controls vs CKD) on white matter fractional anisotropy, adjusting for age. Associations between white matter fractional anisotropy and neurocognitive abilities within the CKD group were also evaluated using regression models that were adjusted for age. The false discovery rate was used to account for multiple comparisons; wherein false discovery values <0.10 were considered significant. RESULTS: Global white matter fractional anisotropy was reduced in patients with CKD relative to controls (standardized estimate = -0.38, 95% CI -0.69:-0.07), driven by reductions within the body of the corpus callosum (standardized estimate = -0.44, 95% CI -0.75:-0.13), cerebral peduncle (SE = -0.37, 95% CI -0.67:-0.07), cingulum (hippocampus) (standardized estimate = -0.45, 95% CI -0.75:-0.14), and posterior limb of the internal capsule (standardized estimate = -0.46, 95% CI -0.76:-0.15). Medical variables and neurocognitive abilities were not significantly associated with white matter fractional anisotropy. CONCLUSIONS: White matter development is vulnerable in children with CKD because of congenital causes, even prior to the need for dialysis or transplantation.

Neurofilament Light Protein as a Potential Blood Biomarker for Huntington's Disease in Children.

BACKGROUND: Juvenile-onset Huntington's disease (JOHD) is a rare and particularly devastating form of Huntington's disease (HD) for which clinical diagnosis is challenging and robust outcome measures are lacking. Neurofilament light protein (NfL) in plasma has emerged as a prognostic biomarker for adult-onset HD. METHODS: We performed a retrospective analysis of samples and data collected between 2009 and 2020 from the Kids-HD and Kids-JHD studies. Plasma samples from children and young adults with JOHD, premanifest HD (preHD) mutation carriers, and age-matched controls were used to quantify plasma NfL concentrations using ultrasensitive immunoassay. RESULTS: We report elevated plasma NfL concentrations in JOHD and premanifest HD mutation-carrying children. In pediatric HD mutation carriers who were within 20 years of their predicted onset and patients with JOHD, plasma NfL level was associated with caudate and putamen volumes. CONCLUSIONS: Quantifying plasma NfL concentration may assist clinical diagnosis and therapeutic trial design in the pediatric population. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.

Associations between neurofilament light-chain protein, brain structure, and chronic kidney disease.

BACKGROUND: Neurofilament light-chain (NfL) protein is a blood-based marker of neuroaxonal injury. We sought to (1) compare plasma NfL levels in children with chronic kidney disease (CKD) and healthy peers, (2) characterize the relationship between NfL level and kidney function, and (3) evaluate NfL as a predictor of abnormal brain structure in CKD. METHODS: Sixteen children with CKD due to congenital kidney anomalies and 23 typically developing peers were included. Plasma NfL was quantified using single-molecule array immunoassay. Participants underwent structural magnetic resonance imaging. Multiple linear regression models were used to evaluate the association between plasma NfL levels, kidney function, and brain structure. RESULTS: An age × group interaction was identified whereby NfL levels increased with age in the CKD group only (estimate = 0.65; confidence interval (CI) = 0.08-1.22; p = 0.026). Decreased kidney function was associated with higher NfL levels (estimate = -0.10; CI = -0.16 to -0.04; p = 0.003). Lower cerebellar gray matter volume predicted increased plasma NfL levels (estimate = -0.00024; CI = -0.00039 to 0.00009; p = 0.004) within the CKD group. CONCLUSIONS: Children with CKD show accelerated age-related increases in NfL levels. NfL level is associated with lower kidney function and abnormal brain structure in CKD. IMPACT: NfL is a component of the neuronal cytoskeleton providing structural axonal support. Elevated NfL has been described in relation to gray and white matter brain volume loss. We have previously described the abnormal cerebellar gray matter in CKD. We explored the relationship between NfL, CKD, and brain volume. There is an accelerated, age-related increase in NfL level in CKD. Within the CKD sample, NfL level is associated with abnormal kidney function and brain structure. Decreased kidney function may be linked to abnormal neuronal integrity in pediatric CKD.

Sex-specific cytokine responses and neurocognitive outcome after blood transfusions in preterm infants.

BACKGROUND: The objective of this study was to determine sex-specific differences in inflammatory cytokine responses to red blood cell (RBC) transfusion in preterm infants in the neonatal period and their relationship to later neurocognitive status. METHODS: Infants with a birth weight <1000 g and gestational age 22-29 weeks were enrolled in the Transfusion of Prematures (TOP) trial. The total number of transfusions was used as a marker of transfusion status. Nineteen cytokines and biomarkers were analyzed from 71 infants longitudinally during the neonatal period. Twenty-six infants completed the Bayley Scales of Infant & Toddler Development, 3rd Edition (Bayley-III) at 12 months' corrected age. RESULTS: Nine cytokine levels were significantly elevated in proportion to the number of transfusions received. Of those, one cytokine showed a sex-specific finding (p = 0.004): monocyte chemoattractant protein-1, MCP-1, rose substantially in females (8.9% change per additional transfusion), but not in males (-0.8% change). Higher concentrations of MCP-1 exclusively were associated with worse Bayley-III scores: decreased cognitive raw scores (p = 0.0005) and motor scaled scores (p < 0.0001). CONCLUSIONS: This study provides evidence of a sex-specific difference in the inflammatory response to RBC transfusions during neonatal life, with MCP-1 levels rising only in females and inversely correlating with neurocognitive status at 12 months old. IMPACT: It is important to understand the risk factors for abnormal neurodevelopment in preterm infants, including anemia and RBC transfusion, in order to improve outcomes and provide potential targets for therapy. Our study investigates and provides the first evidence of sex-specific differences in inflammatory cytokine responses to RBC transfusions in preterm infants in the neonatal period, and their relationship to later cognitive outcomes. This study critically suggests that different transfusion thresholds may have a sex-specific effect on neurodevelopment: females have worse cognitive outcomes with increased number of transfusions, while males have worse outcomes with lower number of transfusions.

Cognitive function and its relationship with brain structure in myotonic dystrophy type 1.

Studies have shown relationships between white matter abnormalities and cognitive dysfunction in myotonic dystrophy type 1 (DM1), but comprehensive analysis of potential structure-function relationships are lacking. Fifty adult-onset DM1 individuals (33 female) and 68 unaffected adults (45 female) completed the Wechsler Adult Intelligence Scale-IV (WAIS-IV) to determine the levels and patterns of intellectual functioning. Neuroimages were acquired with a 3T scanner and were processed with BrainsTools. Regional brain volumes (regions of interest, ROIs) were adjusted for inter-scanner variation and intracranial volume. Linear regression models were conducted to assess if group by ROI interaction terms significantly predicted WAIS-IV composite scores. Models were adjusted for age and sex. The DM1 group had lower Perceptual Reasoning Index (PRI), Working Memory Index (WMI), and Processing Speed Index (PSI) scores than the unaffected group (PRI t(113)  = -3.28, p = 0.0014; WMI t(114)  = -3.49, p = 0.0007; PSI t(114)  = -2.98, p = 0.0035). The group by hippocampus interaction term was significant for both PRI and PSI (PRI (t(111)  = -2.82, p = 0.0057; PSI (t(112)  = -2.87, p = 0.0049)). There was an inverse association between hippocampal volume and both PRI and PSI in the DM1 group (the higher the volume, the lower the intelligence quotient scores), but no such association was observed in the unaffected group. Enlarged hippocampal volume may underlie some aspects of cognitive dysfunction in adult-onset DM1, suggesting that increased volume of the hippocampus may be pathological.

Quantitative muscle MRI as a sensitive marker of early muscle pathology in myotonic dystrophy type 1.

BACKGROUND: Quantitative muscle MRI as a sensitive marker of early muscle pathology and disease progression in adult-onset myotonic dystrophy type 1. The utility of muscle MRI as a marker of muscle pathology and disease progression in adult-onset myotonic dystrophy type 1 (DM1) was evaluated. METHODS: This prospective, longitudinal study included 67 observations from 36 DM1 patients (50% female), and 92 observations from 49 healthy adults (49% female). Lower-leg 3T magnetic resonance imaging (MRI) scans were acquired. Volume and fat fraction (FF) were estimated using a three-point Dixon method, and T2-relaxometry was determined using a multi-echo spin-echo sequence. Muscles were segmented automatically. Mixed linear models were conducted to determine group differences across muscles and image modality, accounting for age, sex, and repeated observations. Differences in rate of change in volume, T2-relaxometry, and FF were also determined with mixed linear regression that included a group by elapsed time interaction. RESULTS: Compared with healthy adults, DM1 patients exhibited reduced volume of the tibialis anterior, soleus, and gastrocnemius (GAS) (all, P < .05). T2-relaxometry and FF were increased across all calf muscles in DM1 compared to controls. (all, P < .01). Signs of muscle pathology, including reduced volume, and increased T2-relaxometry and FF were already noted in DM1 patients who did not exhibit clinical motor symptoms of DM1. As a group, DM1 patients exhibited a more rapid change than did controls in tibialis posterior volume (P = .05) and GAS T2-relaxometry (P = .03) and FF (P = .06). CONCLUSIONS: Muscle MRI renders sensitive, early markers of muscle pathology and disease progression in DM1. T2 relaxometry may be particularly sensitive to early muscle changes related to DM1.

Early pediatric chronic kidney disease is associated with brain volumetric gray matter abnormalities.

BACKGROUND: The impact of pediatric chronic kidney disease (pCKD) on the brain remains poorly defined. The objective of this study was to compare brain morphometry between children with early-stage pCKD and typically developing peers using structural magnetic resonance imaging (MRI). METHODS: The sample age range was 6-16 years. A total of 18 children with a diagnosis of pCKD (CKD stages 1-3) due to congenital anomalies of the kidney and urinary tract and 24 typically developing peers were included. Volumetric data from MRI and neurocognitive testing were compared using linear models including pCKD status, age, maternal education level, and socioeconomic status. RESULTS: Cerebellar gray matter volume was significantly smaller in pCKD, t(38) = -2.71, p = 0.01. In contrast, cerebral gray matter volume was increased in pCKD, t(38) = 2.08, p = 0.04. Reduced cerebellum gray matter volume was associated with disease severity, operationalized as estimated glomerular filtration rate (eGFR), t(14) = 2.21, p = 0.04 and predicted lower verbal fluency scores in the pCKD sample. Enlarged cerebral gray matter in the pCKD sample predicted lower scores on mathematics assessment. CONCLUSIONS: This study provides preliminary evidence for a morphometric underpinning to the cognitive deficits observed in pCKD. IMPACT: The impact of pediatric chronic kidney disease (CKD) on the brain remains poorly defined, with no data linking brain morphometry and observed cognitive deficits noted in this population. We explored the relationship between brain morphometry (using structural magnetic resonance imaging), cognition, and markers of CKD. Cerebellar and cerebral gray matter volumes are different in early CKD. Volumetric decreases in cerebellar gray matter are predicted by lower eGFR, suggesting a link between disease and brain morphometry. Reduced cerebellar gray matter predicted lower verbal fluency for those with pCKD. Enlarged cerebral gray matter in the pCKD sample predicted lower mathematics performance.

FoxO6 regulates Hippo signaling and growth of the craniofacial complex.

The mechanisms that regulate post-natal growth of the craniofacial complex and that ultimately determine the size and shape of our faces are not well understood. Hippo signaling is a general mechanism to control tissue growth and organ size, and although it is known that Hippo signaling functions in neural crest specification and patterning during embryogenesis and before birth, its specific role in postnatal craniofacial growth remains elusive. We have identified the transcription factor FoxO6 as an activator of Hippo signaling regulating neonatal growth of the face. During late stages of mouse development, FoxO6 is expressed specifically in craniofacial tissues and FoxO6-/- mice undergo expansion of the face, frontal cortex, olfactory component and skull. Enlargement of the mandible and maxilla and lengthening of the incisors in FoxO6-/- mice are associated with increases in cell proliferation. In vitro and in vivo studies demonstrated that FoxO6 activates Lats1 expression, thereby increasing Yap phosphorylation and activation of Hippo signaling. FoxO6-/- mice have significantly reduced Hippo Signaling caused by a decrease in Lats1 expression and decreases in Shh and Runx2 expression, suggesting that Shh and Runx2 are also linked to Hippo signaling. In vitro, FoxO6 activates Hippo reporter constructs and regulates cell proliferation. Furthermore PITX2, a regulator of Hippo signaling is associated with Axenfeld-Rieger Syndrome causing a flattened midface and we show that PITX2 activates FoxO6 expression. Craniofacial specific expression of FoxO6 postnatally regulates Hippo signaling and cell proliferation. Together, these results identify a FoxO6-Hippo regulatory pathway that controls skull growth, odontogenesis and face morphology.

Myotonic dystrophy type 1 alters muscle twitch properties, spinal reflexes, and perturbation-induced trans-cortical reflexes.

BACKGROUND: Neurophysiologic biomarkers are needed for clinical trials of therapies for myotonic dystrophy (DM1). We characterized muscle properties, spinal reflexes (H-reflexes), and trans-cortical long-latency reflexes (LLRs) in a cohort with mild/moderate DM1. METHODS: Twenty-four people with DM1 and 25 matched controls underwent assessment of tibial nerve H-reflexes and soleus muscle twitch properties. Quadriceps LLRs were elicited by delivering an unexpected perturbation during a single-limb squat (SLS) visuomotor tracking task. RESULTS: DM1 was associated with decreased H-reflex depression. The efficacy of doublet stimulation was enhanced, yielding an elevated double-single twitch ratio. DM1 participants demonstrated greater error during the SLS task. DM1 individuals with the least-robust LLR responses showed the greatest loss of spinal H-reflex depression. CONCLUSIONS: DM1 is associated with abnormalities of muscle twitch properties. Co-occurring alterations of spinal and trans-cortical reflex properties underscore the central nervous system manifestations of this disorder and may assist in gauging efficacy during clinical trials.

Anemia induces gut inflammation and injury in an animal model of preterm infants.

BACKGROUND: While very low birth weight (VLBW) infants often require multiple red blood cell transfusions, efforts to minimize transfusion-associated risks have resulted in more restrictive neonatal transfusion practices. However, whether restrictive transfusion strategies limit transfusions without increasing morbidity and mortality in this population remains unclear. Recent epidemiologic studies suggest that severe anemia may be an important risk factor for the development of necrotizing enterocolitis (NEC). However, the mechanism whereby anemia may lead to NEC remains unknown. STUDY DESIGN AND METHODS: The potential impact of anemia on neonatal inflammation and intestinal barrier disruption, two well-characterized predisposing features of NEC, was defined by correlation of hemoglobin values to cytokine levels in premature infants and by direct evaluation of intestinal hypoxia, inflammation and gut barrier disruption using a pre-clinical neonatal murine model of phlebotomy-induced anemia (PIA). RESULTS: Increasing severity of anemia in the preterm infant correlated with the level of IFN-gamma, a key pro-inflammatory cytokine that may predispose an infant to NEC. Gradual induction of PIA in a pre-clinical model resulted in significant hypoxia throughout the intestinal mucosa, including areas where intestinal macrophages reside. PIA-induced hypoxia significantly increased macrophage pro-inflammatory cytokine levels, while reducing tight junction protein ZO-1 expression and increasing intestinal barrier permeability. Macrophage depletion reversed the impact of anemia on intestinal ZO-1 expression and barrier function. CONCLUSIONS: Taken together, these results suggest that anemia can increase intestinal inflammation and barrier disruption likely through altered macrophage function, leading to the type of predisposing intestinal injury that may increase the risk for NEC.

Altered brain function, structure, and developmental trajectory in children born late preterm.

BACKGROUND: Late preterm birth (34-36 wk gestation) is a common occurrence with potential for altered brain development. METHODS: This observational cohort study compared children at age 6-13 y based on the presence or absence of the historical risk factor of late preterm birth. Children completed a battery of cognitive assessments and underwent magnetic resonance imaging of the brain. RESULTS: Late preterm children (n = 52) demonstrated slower processing speed (P = 0.035) and scored more poorly in visual-spatial perception (P = 0.032) and memory (P = 0.007) than full-term children (n = 74). Parents of late preterm children reported more behavioral difficulty (P = 0.004). There were no group differences in cognitive ability or academic achievement. Imaging revealed similar intracranial volumes but less total tissue and more cerebrospinal fluid (P = 0.004) for late preterm children compared to full-term children. The tissue difference was driven by differences in the cerebrum (P = 0.028) and distributed across cortical (P = 0.051) and subcortical tissue (P = 0.047). Late preterm children had a relatively smaller thalamus (P = 0.012) than full-term children. Only full-term children demonstrated significant decreases in cortical tissue volume (P < 0.001) and thickness (P < 0.001) with age. CONCLUSION: Late preterm birth may affect cognition, behavior, and brain structure well beyond infancy.

Clinical Review of Juvenile Huntington's Disease.

 Juvenile Huntington's disease (JHD) is rare. In the first decade of life speech difficulties, rigidity, and dystonia are common clinical motor symptoms, whereas onset in the second decade motor symptoms may sometimes resemble adult-onset Huntington's disease (AOHD). Cognitive decline is mostly detected by declining school performances. Behavioral symptoms in general do not differ from AOHD but may be confused with autism spectrum disorder or attention deficit hyperactivity disorder and lead to misdiagnosis and/or diagnostic delay. JHD specific features are epilepsy, ataxia, spasticity, pain, itching, and possibly liver steatosis. Disease progression of JHD is faster compared to AOHD and the disease duration is shorter, particularly in case of higher CAG repeat lengths. The diagnosis is based on clinical judgement in combination with a positive family history and/or DNA analysis after careful consideration. Repeat length in JHD is usually > 55 and caused by anticipation, usually via paternal transmission. There are no pharmacological and multidisciplinary guidelines for JHD treatment. Future perspectives for earlier diagnosis are better diagnostic markers such as qualitative MRI and neurofilament light in serum.

Assisted annotation in Deep LOGISMOS: Simultaneous multi-compartment 3D MRI segmentation of calf muscles.

BACKGROUND: Automated segmentation of individual calf muscle compartments in 3D MR images is gaining importance in diagnosing muscle disease, monitoring its progression, and prediction of the disease course. Although deep convolutional neural networks have ushered in a revolution in medical image segmentation, achieving clinically acceptable results is a challenging task and the availability of sufficiently large annotated datasets still limits their applicability. PURPOSE: In this paper, we present a novel approach combing deep learning and graph optimization in the paradigm of assisted annotation for solving general segmentation problems in 3D, 4D, and generally n-D with limited annotation cost. METHODS: Deep LOGISMOS combines deep-learning-based pre-segmentation of objects of interest provided by our convolutional neural network, FilterNet+, and our 3D multi-objects LOGISMOS framework (layered optimal graph image segmentation of multiple objects and surfaces) that uses newly designed trainable machine-learned cost functions. In the paradigm of assisted annotation, multi-object JEI for efficient editing of automated Deep LOGISMOS segmentation was employed to form a new larger training set with significant decrease of manual tracing effort. RESULTS: We have evaluated our method on 350 lower leg (left/right) T1-weighted MR images from 93 subjects (47 healthy, 46 patients with muscular morbidity) by fourfold cross-validation. Compared with the fully manual annotation approach, the annotation cost with assisted annotation is reduced by 95%, from 8 h to 25 min in this study. The experimental results showed average Dice similarity coefficient (DSC) of 96.56 ± 0.26 % $96.56\pm 0.26 \%$ and average absolute surface positioning error of 0.63 pixels (0.44 mm) for the five 3D muscle compartments for each leg. These results significantly improve our previously reported method and outperform the state-of-the-art nnUNet method. CONCLUSIONS: Our proposed approach can not only dramatically reduce the expert's annotation efforts but also significantly improve the segmentation performance compared to the state-of-the-art nnUNet method. The notable performance improvements suggest the clinical-use potential of our new fully automated simultaneous segmentation of calf muscle compartments.

Longitudinal changes in white matter as measured with diffusion tensor imaging in adult-onset myotonic dystrophy type 1.

Myotonic dystrophy type 1 is characterized by neuromuscular degeneration. Our objective was to compare change in white matter microstructure (fractional anisotropy, radial and axial diffusivity), and functional/clinical measures. Participants underwent yearly neuroimaging and neurocognitive assessments over three-years. Assessments encompassed full-scale intelligence, memory, language, visuospatial skills, attention, processing speed, and executive function, as well as clinical symptoms of muscle/motor function, apathy, and hypersomnolence. Mixed effects models were used to examine differences. 69 healthy adults (66.2% women) and 41 DM1 patients (70.7% women) provided 156 and 90 observations, respectively. There was a group by elapsed time interaction for cerebral white matter, where DM1 patients exhibited declines in white matter (all p<0.05). Likewise, DM1 patients either declined (motor), improved more slowly (intelligence), or remained stable (executive function) for functional outcomes. White matter was associated with functional performance; intelligence was predicted by axial (r = 0.832; p<0.01) and radial diffusivity (r = 0.291, p<0.05), and executive function was associated with anisotropy (r = 0.416, p<0.001), and diffusivity (axial: r = 0.237, p = 0.05 and radial: r = 0.300, p<0.05). Indices of white matter health are sensitive to progression in DM1. These results are important for clinical trial design, which utilize short intervals to establish treatment efficacy.

Clinical predictors of driving status in Huntington's disease.

The aim of this study was to identify the motor, cognitive, and behavioral determinants of driving status and risk factors for driving cessation in Huntington's disease (HD). Seventy-four patients with HD were evaluated for cognitive, motor, psychiatric, and functional status using a standardized battery (Unified Huntington's Disease Rating Scale [UHDRS] and supplemental neuropsychological testing) during a research clinic visit. Chart review was used to categorize patients into two driving status categories: (1) "currently driving" included those driving and driving but with clinician recommendation to restrict, and (2) "not driving" included those with clinician recommendation to cease driving and those not currently driving because of HD. Multi- and univariate logistic regression was used to identify significant clinical predictors of those driving versus not driving. Global cognitive performance and UHDRS Total Functional Capacity scores provided the best predictive model of driving cessation (Nagelkerke R(2) = 0.65; P < 0.0001). Measures of learning (P = 0.006) and psychomotor speed/attention (P = 0.003) accounted for the overall cognitive finding. In univariate analyses, numerous cognitive, motor, and daily functioning items were significantly associated with driving. Although driving status is associated with many aspects of the disease, results suggest that the strongest association is with cognitive performance. A detailed cognitive evaluation is an important component of multidisciplinary clinical assessment in patients with HD who are driving.